DIY Audio Projects Forum

Balance wiring and resistors fitted,

The resistors are Tantalum (None magnetic for the Balance and magnetic for the volume) and I made a couple of screened wires with Teflon/silver stranded from the balance pot to the volume control.
The one pic shows the resistors in place then the wiring. The balance Pot is wired AKA audio note M7.
Its all soldered with Audio Note solder.
The screening is just heavy duty aluminium foil wrapped around the Teflon wire with a drain wire to volume ground.
Two connections on the balance control are not soldered because the input board will connect to them in the next step.
NB the two 100K colours are reversed<<because the signal input is from opposite directions.
Its a bit mad but I like to codes to follow the circuit.
The balance is the same as this link:
https://drtube.com/schematics/an/m7.gif
But the line amp is as discussed previously not the same as the link.

Regards
M. Gregg

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What is the sound of one hand clapping?

I am looking at a redesign of the input board,

This is the top chassis layout so far. So there is input wiring to the board both audio and control to do.
I might look at some illumination of the chassis for fun buts that's probably the last thing on the list.
I had to buy some more stranded silver wire for the input but I bite the bullet.
More to do but its coming to an end eventually
I asked myself the question why are you building this? Er not sure..LMAO

Regards
M. Gregg

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What is the sound of one hand clapping?

I think you want to get every last bit of sound quality you can get, while using components and schematics avalible to you.
Which makes sense.

Thanks for the positive comment.
Yes its feels like quite a strange build.

I just had a weird thought. If I build the completed preamp do all the tests on a scope for ground noise and signal.
Then not put any music through it and look at it on a shelf it would be in superposition is it good or bad:
https://www.youtube.com/watch?v=IOYyCHGWJq4


Regards
M. Gregg

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What is the sound of one hand clapping?

Hi Gregg!
I think I've seen that kind of transformer before. Danbury?! I used to buy (Mike) from a guy in UK, but the transformer workshop closed down a few years ago. At least the smaller transformers were perfectly priced and of reasonable quality.

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Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll

Well it could be someone carrying on the product maybe I have seen Danbury transformers as well.
The make is Primary windings I have no connection:
http://primarywindings.com/
I know Danbury transformers were used many years ago in Maplin valve projects but I don't know the history of Primary windings or why they look like Danbury transformers.
I must admit I am glad that there is another manufacturer available.

Regards
M. Gregg

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What is the sound of one hand clapping?

Input Card completed on PTFE.

Wired in Duelund silver wire and Audio Note solder.
Using relay bases.
The PTFE board is thicker than KITE so I drilled the holes for the bases then countersunk the rear side with a 2mm drill and pushed the wire into and around the base pins then soldered.
Next step to mount and wire the input card.

Regards
M. Gregg

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What is the sound of one hand clapping?

Why not use cheap prototype boards from aliexpress, easier to install.
Does the PTFE board material offer imrpvoed soundquailty?

Many people are happy with standard boards, solders, wire types and capacitors etc.
I find that fiberglass seems to give a "hard sound"<<I tried to think of a better description but its difficult to describe.
A bit like Metal film vs carbon composite. The effect is a bit warmer sounding.
Micro detail is another issue.
But it depends on how you feel about the gain in sound vs the difficulty in creating the boards.
The problem is that you need to ensure longevity of the board "water absorption" and Di-electric withstand voltage.
But the ideas are:
The problem with PCB board material is it creates a Di-electric between tracks in effect you have capacitors all across a board.
The other problem is the tracks "wire" carrying the signal. Many people are happy to use fiberglass circuit board with copper tracks the temptation would be oxygen free or continuous casting processes or silver.
So it depends on how you feel about different Dielectrics in capacitors ie polypropylene vs polycarbonate or Teflon.
The other effect is the vibration transmission to components. Different materials have a different sound when you tap them, this sound is a vibration transmission frequency some people choose different materials for case work to try to prevent this. In years gone by people used to put Black tack or vibration damping under components. I tried lots of things and ideas about the Di-electric etc I thought OK its all rubbish so I melted a wax candle onto a circuit board and spread it with a hair dryer. Instantly all the sparkle and high frequency information disappeared. It scrapped the board but the components were fine and I cleaned them and reused. Take from that what you will.
Audio Note take it to the extreme like in this link look at the PCB material and the components lead out wires:
https://www.dagogo.com/audio-note-m9-ri ... -part-1/2/
And leadouts:
https://audionote.wordpress.com/2011/10 ... rousel-646

Its interesting to note things like chokes have a start and end of a winding, So in a PSU one end of the choke is full of noise the other end is closer to the smoothed supply, so if you put the smoothed side out side it shields the core.
There are lots of things like one end of a transformer primary winding is closer to Ground (one side is neutral).

So it depends on your personal feelings, however audio gain should never compromise electrical safety.

Regards
M. Gregg

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What is the sound of one hand clapping?

I do actually hear a little bit the sound charater from the very cheap prototype boards I'm using to build my amps on.
Some sound chrater but still pleseant sound.